1. Field of the Invention
The present general inventive concept relates to an ink cartridge and an inkjet printer using the same, and more particularly, to an installation structure between a bottom surface of an ink cartridge and a filter pipe located on the bottom surface of the ink cartridge to press foam filled in the cartridge.
2. Description of the Related Art
An inkjet printer is a device used to print an image by ejecting fine ink droplets on a surface of a recording medium in a desired shape, which uses an ink cartridge as a means for storing and ejecting ink. Generally, the ink cartridge has an ink storing space therein, which is integrally formed with ejecting means for ejecting the stored ink or separately formed with the ejecting means.
FIG. 1 is a cross-sectional view illustrating an integrated ink cartridge, a filter pipe 12 is formed on a bottom surface 10a of a synthetic resin cartridge case 10, and the ink is supplied to the ejecting means through the filter pipe 12. The filter pipe 12 is integrally formed with the cartridge case 10 provided with an inkjet head 14 on its bottom surface to eject the ink to an exterior thereof. Meanwhile, foam 16 is filled in the cartridge case 10 to form an appropriate negative pressure in the ink cartridge to prevent the ink from leaking out of the ink cartridge, thereby stably ejecting the ink through the inkjet head 14.
Therefore, the ink is absorbed and stored in the foam 16, as shown in FIG. 1, and the filter pipe 12 is protruded from the bottom surface 10a by a predetermined extent to press the foam 16 around the filter pipe when the foam 16 is inserted into the cartridge case 10. The pressed foam strongly absorbs the ink due to a large capillary force in comparison with unpressed foam, and as a result, the ink may be stably supplied into the filter pipe 12.
When the ink is introduced into the ink cartridge fabricated as above through ink introducing means (not shown), the ink is filled first from the bottom surface 10a of the ink cartridge to be absorbed into the entire foam evenly. However, a space at which the foam is not filled is generated in regions A and B around the filter pipe due to morphologic properties of the filter pipe 12.
In particular, as shown in FIG. 2, a groove C having a depth extended from the bottom surface 10a to a position in the vicinity of the head attachment portion is formed around the filter pipe 12. Although the groove C is formed to prevent the filter pipe 12 from shrinking while manufacturing the cartridge case by injection molding to thereby ensure dimension stability, when the ink is filled in the cartridge, the ink is gathered with air in the spaces A, B and C without being absorbed into the foam.
Since the ink gathered in the spaces A, B and C does not contact the foam, it is difficult to make the foam absorb the ink, thereby decreasing ink use efficiency. In addition, though the ink is absorbed and used, there remains an empty space where the air is filled. In this state, the air filled in the space is shrunk or expanded depending upon changes of temperature and pressure, thereby causing a level of the ink stored in the foam to be changed, and causing the ink to leak to decrease a usage amount of the ink. Further, a filter (not shown) for filtering impurities contained in the ink is mounted on an upper surface of the filter pipe 12, and therefore the air may be gathered on the filter to block a part of the filter, or the air may be introduced into the head to deteriorate ejection performance of the head.